JPS6325922B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to certain improvements in molds for use in the manufacture of ceramic dishes and the like, of the type that can be mounted on horizontal presses.

According to the prior art, stamping dies for the production of ceramic blanks in horizontal presses are known, consisting of two coaxial cylindrical dies with the same diameter, constituting a die and a counter die, respectively, at least one of which is The die is axially displaceable and has end walls facing each other to form further front and back features, respectively, to be formed. The cylindrical die is surrounded by a movable die box, hereinafter referred to as the main die box, having a cylindrical cavity;
Its diameter is slightly larger than the diameter of the cylindrical die. The main die box has a vertical internal duct in communication with a hopper through which powdered ceramic material is delivered into a cavity defined by a predetermined spacing between the end walls of the cylindrical die and the counter die. The cylindrical inner wall of the die box has the function of delimiting the peripheral limits of the cavity into which the powder material is to be fed and defining the periphery of the forming plate.

The cylindrical wall of the main die box must necessarily have a larger diameter than the cylindrical coaxial die, in order to be able to move along the cylindrical coaxial die. The plate has a peripheral edge that is flattened and has some flash, so that the shaped plate has to be machined by a suitable grinding machine to round the peripheral edge, which This is a time-consuming and expensive process.

The mold according to the invention aims to avoid the above-mentioned drawbacks and is characterized in that an auxiliary die box is provided which surrounds at least one cylindrical die and is slidable over it;
The box is displaceable with respect to the main die box so as to be moved away from and toward the main die box, and the box is displaceable with respect to the main die box so as to be moved toward and away from the main die box. An open annular groove is provided, such that in the contact state of the main die box and the auxiliary die box, said annular groove overlaps the periphery of the cavity of the mold, extends the latter radially and forms the periphery of the further to be produced. However, it forms an annular cavity.

Next, the improved mold according to the present invention will be explained in more detail with reference to the accompanying drawings. In the drawings, similar parts or parts with similar functions are designated by the same reference numerals and, at the appropriate moment, hold the cylindrical die and the die box;
All elements and mechanisms designed to guide and cause their axial displacement are not shown, since they are known parts of horizontal presses and do not affect the features of the invention.

FIGS. 1 and 2 show a mold for producing ceramic silica, which is embodied in accordance with the prior art. The stamping die is composed of a die 1, a counter die 2 and a main die box 3. The die and counter die are cylindrical with circular cross sections of the same diameter and are coaxial.

The opposing end walls of dies 1 and 2 are shaped to form respectively the front and rear features of the further to be pressed.

The main die box 3 comprises a cylindrical cavity designed to cut the periphery of the die and surrounding the dies 1, 2 and having a diameter slightly larger than the diameter of said dies, and having suitably spaced cylindrical cavities. A vertical conduit 4 is provided for feeding powdered ceramic material into the cavity formed between the opposing walls of the shaped die. The powdered ceramic material is fed from a hopper (not shown) after the main die box has been displaced from the position 3' shown in dotted lines to the position shown in solid lines.

In FIG. 2, the die is shown in the pressing stage, with the main die box 3 being displaced into a position that closes the periphery of the cavity of the die.

As can be seen by considering Figures 1 and 2, after the stamping stage, the produced sills simply have a flattened periphery, usually accompanied by a large number of burrs, and these burrs are elaborately cut. It must be removed by grinding and finishing operations.

In FIG. 3, the mold improved according to the invention is shown in a rest or inactive state. Said stamping die consists of a cylindrical die 10 and a cylindrical counter die 11, both dies having the same diameter and coaxial, and their opposing walls, except for the periphery of the further to be manufactured, are pressed. The shape is such that it forms the front and back shapes of the further surface to be used.

A main die box 14 is slidably disposed along the cylindrical die and includes a vertical conduit 15. The conduit 15 communicates at the top with a hopper (not shown) and opens at the bottom onto the cylindrical dies 11, 12 for purposes described below. An auxiliary die box 16 is slidably arranged on the counter die 11 and can be moved relative to the die box 14.

As shown in Figures 3 and 4, the main die box 1
4 and the auxiliary die box 16 are provided with annular grooves 20 and 21, respectively, which grooves are shaped so that when the opposing walls come into contact, they form the periphery of the die to be produced and the stamping die. is adapted to constitute a radial extension of the cavity.

In practice, the cylindrical dies 10, 11 are spaced apart and the material is suitably displaced through the conduit 15 of the main die box 14 to define a cavity to be filled with the proper amount of material for pressing the die. From the state shown in Figure 4 where it is being fed,
The die is positioned as shown in FIG. 5 according to arrow 17 and displaced according to arrow 18 until the auxiliary die box 16 comes into contact with the main die box 14, then both die boxes are displaced, so that the groove is formed. An annular cavity formed by 20, 21 overlaps a cavity formed by cylindrical dies 10, 11.

In these conditions, the cylindrical die 11 is displaced into the pressing position, so that the powdered ceramic material is pressed and expanded to fill the annular cavity and to round it appropriately, as clearly shown in FIG. Form its periphery with a mark.

6-11 show the successive stages of the die pressing cycle.

FIG. 6 shows the die in its rest or inactive position, with the cylindrical dies 10 and 11 being spaced considerably apart from each other.

FIG. 7 shows that in order to define the filling cavity of the mold,
The stamping die is shown where the cylindrical die 11 is brought close to the cylindrical die 10.

FIG. 8 shows a subsequent step in which the main die box 1 is moved so that the powdered ceramic material is fed into the die.
4 has been displaced to a position that overlaps the conduit 15 with said filling cavity.

Figure 9 shows the subsequent stage, main die box 1
4 and the auxiliary die box 16 are in contact and both die boxes are displaced to overlap the annular cavity with the cavity filled with material.

FIG. 10 shows a pressing step corresponding to FIG. 5.

FIG. 11 shows the final stage, in which the cylindrical die 11 and the auxiliary die box 16 are retracted to the position of FIG. 6, so that the pressed blank falls from the die under gravity.

In the illustrated embodiment, grooves 20 and 21 (FIGS. 3 and 4) are provided directly in the main die box 14 and auxiliary die box 16 bodies, respectively.

In another embodiment of the invention, the grooves 20, 21
They can also be provided in separate annular members designed to be fixedly attached to the bodies of the main die box 14 and the auxiliary die box 16, for example by screws.

The above description has been made for purposes of illustration and not as a limitation on the scope of the invention. Many changes and modifications will occur to those skilled in the art. It is intended that such modifications and changes be included within the true spirit and scope of the invention as defined by the claims.

[Brief explanation of the drawing]

1 and 2 are longitudinal cross-sectional views of a prior art mold for producing ceramic blanks in a feeding state and a pressing state, respectively. FIG. 3 is an enlarged longitudinal sectional view of a mold for producing ceramic plates according to the invention in a rest or inactive position; FIG. 4 shows the same die in which the cylindrical dies are spaced apart to define the filling cavity. FIG. 5 shows the same stamping die in a press working state. FIGS. 6 to 11 are scaled views showing the successive states of the press when performing a press working cycle for ceramic blanking. 1... Die, 2... Die, 3... Main die box, 4... Conduit, 10... Die, 11... Die, 12... Opposing wall, 13... Opposing wall, 14...
Main die box, 15... conduit, 16... auxiliary die box, 20... annular groove, 21... annular groove.

Claims (1)

[Scope of Claims] 1. A press mold for press-working ceramic plates etc. from powdered ceramic material, which is composed of two cylindrical dies that are coaxial and have the same diameter, and at least one of the dies has a cylindrical die formed on the other side. a main die box surrounding the cylindrical die; the die box is slidable along the cylindrical die to close the periphery of the cavity of the mold when in the pressing condition, and the die box is slidable along the cylindrical die to close the periphery of the cavity of the mold when in the pressing state, and the die box is slidable along the cylindrical die to close the periphery of the cavity of the mold when in the pressing condition, and the die box is operable to move powder ceramic from the hopper into the cavity of the mold. In said die, an auxiliary die box 16 is provided which surrounds at least one cylindrical die and is slidable over said auxiliary die, provided with a vertical conduit allowing the feeding of material. The box is displaceable with respect to the main die box 14 so as to be moved away from or toward the main die box 14, and the enclosed cylindrical die 10 is disposed on opposing lateral walls of the main die box and the auxiliary die box. , 11, annular grooves 20, 2 open toward
1 is provided, and in the state of contact between the main die box and the auxiliary die box, said annular groove overlaps the periphery of the die cavity, extends said die cavity in the radial direction and forms the periphery of the further to be manufactured. However, it was made to form an annular cavity,
The above-mentioned pressing mold is characterized in that: 2 The annular grooves 20 and 21 are connected to the main die box 14.
The pressing mold according to claim 1, wherein the mold is provided directly on the main body of the auxiliary die box 16 and the main body of the auxiliary die box 16, respectively. 3. The mold according to claim 1, wherein the annular grooves 20 and 21 are provided on separate annular members that are respectively attached and fixed to the main die box and the auxiliary die box.